In Mark 8, how did Jesus cure the blind man?

By spitting on his eyes

He [Jesus] ... spit on his eyes, and put his hands upon him, he asked him if he saw ought.

And he looked up, and said, I see men as trees, walking.

After that he put his hands again upon his eyes, and made him look up: and he was restored, and saw every man clearly. Mark 8:23-25